Fig. 4.

Mean transfers, conditional on offers 5, 6, and 7: point values and 95% confidence intervals. All confidence intervals are calculated via bootstrapping to account for the nonnegativity constraints and are centered on the empirical observation; in some cases the intervals are not symmetric because of the skewness of the data. We do not report transfers after offer 7 in 1S because the occurrences are too few to be meaningful: 0 such offers in laboratory first round; 7 (2%) in laboratory all rounds, and 2 (1%) in MTurk. The corresponding numbers in 2S are 7 (9%), 127 (21%), and 23 (6%). In 1S, offers of 6 are also rare (the numbers of offers 6 are reported in Fig. 5). However, the hypothesis of equal transfers in 1S and 2S following offers 6 (against the one-side alternative of higher transfers in 2S) is strongly rejected in both laboratory data series and marginally fails to be rejected in MTurk: P = 0.011, P = 0.001, P = 0.053 [for laboratory first round, laboratory all rounds, and MTurk, in order; one-sided t test for laboratory first round and MTurk, bootstrapped simulations for laboratory all rounds (SI Appendix)].